diff --git a/src/api.F90 b/src/api.F90
index f089555bce..0fa537e528 100644
--- a/src/api.F90
+++ b/src/api.F90
@@ -207,7 +207,7 @@ contains
 
     if (found) then
       index = p % coord(p % n_coord) % cell + 1
-      instance = p % cell_instance - 1
+      instance = p % cell_instance
       err = 0
     else
       err = E_GEOMETRY